RESUMEN
Thietanes were used in the past as mimics for an unstable oxetane intermediate formed during the repair of mutagenic (6-4) lesions. The thietane derivatives were found to be not repaired, raising the question of how well thietanes are cleaved by single electron donation compared to oxetanes. We have prepared two flavin-containing oxetane and thietane model compounds for the (6-4) photolyase catalyzed repair process and we show that both are efficiently cleaved by a reduced and deprotonated flavin. Thietanes are therefore excellent models. The lack of their repair can be attributed to lack of binding.
Asunto(s)
Éteres Cíclicos/química , Cromatografía Líquida de Alta Presión , Hidrólisis , Espectroscopía de Resonancia Magnética , Espectrometría de Masa por Ionización de ElectrosprayAsunto(s)
Reparación del ADN , Desoxirribodipirimidina Fotoliasa/metabolismo , Flavinas/fisiología , Cromatografía Líquida de Alta Presión , Desoxirribodipirimidina Fotoliasa/fisiología , Éteres Cíclicos/química , Éteres Cíclicos/efectos de la radiación , Modelos Químicos , Oxidación-Reducción , Dímeros de Pirimidina/metabolismoRESUMEN
PNA:DNA strands were prepared containing a flavin electron donor and a thymine dimer acceptor, which gives a strand break upon single electron reduction. With these constructs, it was confirmed that an excess electron transfer through the base stack can be efficient in an interstrand fashion. The effect of an increased distance, a changed sequence, and stacking was explored.